Apparatus for drying explosive substances.



PATBNTED AUG. 20, 1907.:

P. BUTLER. APPARATUS FOR DRYING BXPLOSIVB SUBSTANCES.

APPLICATION FILED JULY 15. 1898.

Inner-c2502" lkz fimaar,

m: Norm]: PETERS c UNITED STATES PAUL BUTLER, OF LOWELL, MASSACHUSETTS.

APPARATUS FOR DRYING EXPLOSIVE SUBSTANCES.

Specification of Letters Patent.

Patented Aug. 20, 1907.

Application filed July 15,1898. Serial No. 686,019.

To all whom it may concern:

Be it known that I, PAUL BUTLER, of Lowell, county of Middlesex,. and State of Massachusetts, have invented an Improvement in Apparatus for Drying Explosive Substances, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

The present invention relates to an apparatus for drying explosive substances, such as the fulminate used in cartridge primers, caps, etc., which is ordinarily applied in a moist condition, and dried afterwards. Heretofore these primers have been dried by subjecting them to a low degree of heat in a drying room, and the operation is dangerous owing to the fact that so long a time is required for the drying operation that great quantities of fulminate have to be stored in the drying room all the time; and ii an explosion occurs serious damage is quite sure to bethe result. Furthermore, much valuable time is lost in the operation.

The object of the present invention is to obviate the dangers attendant upon the method of drying above described, and also to save time in the operation; it being practicable to dry small quantities of the substance with great rapidity, so that if an explosion occurs no great damage is likely to be done, while, in the manufacture of cartridges, for example, no time is wasted in waiting for a supply of dry primers.

The method of drying embodying the invention consists in subjecting the primers to the right degree of heat and at the same time exhausting the air surrounding them and thus carrying away the moisture or vapor.

The apparatus embodying the invention comprises a substantially air tight chamber arranged to be uniformly heated throughout to an even temperature, preferably through the agency of a circulating fluid, the said chamber being adapted to receive the primers and provided with means for exhausting the air therefrom together with the vapor or moisture given out by the wet fulminate.

In order to determine with accuracy when the process is practically finished, the apparatus is provided with a vacuum gage to show regardless of variation in atmospheric conditions when the air and moisture are substantially exhausted from the chamber.

The chamber is herein shown as heated by hot water circulation, a supplemental chamber or jacket being connected by pipes with a water reservoir, preferably having a steam pipe therein to heat the water, the pipes being arranged so as to establish a circulation and thereby maintain a substantially even heat. The chamber may be exhausted in any suitable or usual way, as by means of an inspirator, and is preferably provided with covers or closures which are held in place solely by atmospheric pressure as the air is exhausted from within, so that in case an explosion should occur, the said closures are merely blown off without causing any material damage.

Figure l is a general view of the apparatus in the nature of a diagram with portions shown in section in order to illustrate the various parts in their relation to each other; and Fig. 2 is a top plan view of the drying chamber with the covers or closures removed.

The drying chamber a is herein shown as a rectangular box adjacent to and directly over a suitable h eating chamber b, the said parts being preferably bolted together as indicated, the former having a top cover or closure (1 between which and the walls of the cham ber is interposed a washer a of rubber or other suitable material so as to form a substantially air tight connection between the two, the said cover being held in place by atmospheric pressure when the air is exhausted from the chamber a. The said cover a is not intended to be removed in the ordinary use of the apparatus, but is arranged in this way in order to present no material resistance in case of an explosion.

To insert and take out the primers, the chamber a is further provided with a feed opening a arranged to be closed by means of a cover a shown as provided with a rubber face a and a knob or handle (1 the said cover also being held in position by atmospheric pressure.

To exhaust the air and moisture from the chamber a, the said chamber is shown as connected by a pipe 0 with an inspirator d of any suitable or usual kind; it being obvious, however, that the specific means for exhausting the air may be varied without departing from the invention.

In order to heat the chamber a, the heating chamber b is arranged to receive heated fluid, such as hot water from a reservoir 6 shown as containing a closed steam pipe f whereby the Water therein is heated. The reservoir e is connected with the chamber b by a pipe e leading from a point at or near the top of the reservoir to the said chamber, there being a pipe 6 leading from the bottom of the chamber b to the bottom of the reservoir e. The pipe 6 is herein shown as coupled to a standpipe at the top of the reservoir. As the water becomes heated, therefore, a circulation will be started, the hotter water flowing through the pipe 6 into the chamber b, and the cooler Water flowing from the chamber I; back to the reservoir through the pipe 2 so that a substantially uniform temperature is maintained in the chamber b and consequently in the drying chamber a.

The pipe 6 is shown as provided with a heat indicator or thermometer 6 so that the temperature of the water can be observed and regulated by properly regulating the supply of steam in the pipe f. In starting the operation, therefore, after the primers have been placed in the drying chamber a, the steam is turned on in the pipe f and the inspirator d is started, so that the chamber (1 becomes heated, and atthe same time the air and moisture are drawn or sucked out of the same, the atmospheric pressure holding the covers a and a in position.

To determine when the process has been carried sufficiently far to thoroughly dry the primers, the apparatus is shown as provided with a vacuum-gage g which is shown as consisting of a tube immersed in a vessel 9 containing mercury, the said tube having a suitable scale g asshown. Since the gage tube g is normally 'filled with air, it is obvious that a comparatively large amount of mercury must rise therein as the vacuum is produced, thereby substantially lowering the level of the mercury in the vessel. To determine the actual length of the column of mercury, therefore, the scale g instead of being fixed is shown as supported upon a float g resting on the surface of the mercury, so that the markings of the scale properly indicate the actual length of the column of mercury. The scale is held in its vertical position by means of guidesg secured to the wall 01' support adjacent to the tube. To obviate inaccuracies due to variations of atmospheric pressure,

the gage is further provided with an ordinary barometer g mounted on the wall or support adjacent to the gage tube and scale, so that the gage-scale can be read in comparison with the atmospheric pressure as indicated by the barometer.

The end of the tube g is connected by means of a pipe g with the pipe 0 which leads from the chamber a, so that as the air is exhausted from said chamber it will be likewise exhausted from the tube 9 and the mercury will rise therein in response to atmospheric pressure upon the surface ofthe mercury outside of the tube.

By properly calibrating the scale, therefore, it can be accurately'determined when the air and moisture have been exhausted to a sufficient extent from the chamber a, and the cover a may then be pulled off, and the primers removed.

By the use of the method and apparatus hereinbefore described, the primers can be rapidly dried at a comparatively low temperature, so that there is but slight danger of explosions, and it an explosion should occur, the parts are so arranged that practically no damage will be done, since the top cover to the chamher a is only held by atmospheric pressure.

It is not intended to limit the invention, so far as relates to the apparatus, to the specific construction and arrangement herein shown, since the method does not depend upon mechanical functions; and the apparatus itself may obviously be modified without departing from the invention.

Claims.

An apparatus for drying cartridge shell primers, and

the like, comprising a chamber; a compartment adjacent In testimony whereof, 'I have signed my name to this specification in the presence of two subscribing witnesses.

PAUL BUTLER.

Witnesses 1H. J. LIvERMoIm, NANCY P. FORD. 

